Report on the zoological collections made in the Indo-Pacific Ocean ...

MOLLUSCA. 50167. Cerithium albovaricosum. (Plate XLIV. fig. Q.)Ceritliium gracile, Pease (non Laniarck), Proc. Zool. Soc. 1800, p. 432.Shell thin, clongate-pyi'amidal, whitish or livid white, sparselyspotted between the costte Avith small narrow lines. Whorls about14, convex at the sides, separated by a deep, subcanaliculate suture,slowly increasing, longitudinally finely costate, and spirally lirate,exhibiting at irregular subdistant intervals larger snow-whitevarices. Costre about ten to fifteen on the upper whorls, andsomewhat nodulous through being crossed by the fine transverselirjB, of which there are about four principal ones, several finer intervening.Last whorl with a prominent varix at the left sideopposite the labrum, which is thinnish and somewhat expandedand grooved within. Aperture roundish ovate, oblique, contractedanteriorly into a narrow also oblique canal, sometimes (not always)stained with black. Columella well incurved, covered with a thincallosity bearing an elongate transverse tubercle at the upper part.Length 141 millim., diam. 44-.Providence Reef, Mascarenes, in 24 fms. ; Sandwich Islands{Pease).C. rostratmn of Sowerby is allied to this species, but may be distinguishedby its more angular whorls, different costa?, less deepsuture, and the different and more regular dotting between thenodules round the middle of the whorls. Specimens from the SandwichIslands of this species in the British Museum have not a blackanterior canal, and the costae are rather finer than in the Mascarenespecimen.68. Cerithium amirantium. (Plate XLIV. fig. R.)Shell small, elongate, light pink, faintly dotted with brown.Whorls about 1 2, slightly convex, nodulously costate, spirally lirate,exhibiting at distant intervals paler thickish varices. Costae about15 on trbe upper whorls, crossed by two principal transverse Hrae,which are nodulous upon the ribs, giving the whorls a biangulateappearance at the sides. In addition to these two there are several(about seven) finer lira), but which scarcely form nodules upon thecostae. The body-whorl has the usual varix on the left side welldeveloped, swoUen. The apci'ture is round-ovate, acuminate aboveand prolonged anteriorly into an oblique, short, recurved canal.Columella arcuate, coated with a rosy callus, oearing an elongatetransverse tubercle above. Labrum thickened by a smaU externalvarix. Length 15 millim., diam. 4^.Darros Island, Amirantes, in 22 fms.This pretty little sjiecies agrees with C. fenellam, Sowerby, incolour, but is narrower and differently sculptured.69. Ceritliium (Rhino clavis) acutinodulosum.(Plate XLIV. fig. S.)Shell elongate-pyramidal, white, spotted with l)rown between